Energy absorbing steering column

ABSTRACT

An energy absorbing steering column is mounted in a motor vehicle between spaced apart portions of body structure. One end of the steering column abuts the toe board of the floor pan and threadedly adjustable release means connected to the other end of the column engages a body supported bracket. An intermediate portion of the column is constructed to plastically collapse under an impact load with the adjustable means freely disengaging from its support bracket.

United States Patent [191 Pardy [451 Sept. 25, 1973 ENERGY ABSORBINGSTEERING COLUMN [75] Inventor: Ronald Peter Pardy, Hockley,

England [73] Assignee: Ford Motor Company, Dearborn,

Mich.

221 Filed: Sept. 19, 1972 211 App]. No.: 290,305

[52] US. Cl. 74/492 [51] Int. Cl 862d 1/18 [58] Field of Search 74/492,493

[56] References Cited UNITED STATES PATENTS Weston 74/492 PrimaryExaminer-Milton Kaufman I I Att0rneyKeith L. Zerschling et al.

[5 7 ABSTRACT An energy absorbing steering column is mounted in a motorvehicle between spaced apart portions of body structure. One end of thesteering column abuts the toe board of the floor pan and threadedlyadjustable release means connected to the other end of the columnengages a body supported bracket. An intermediate portion of the columnis constructed to plastically collapse under an impact load with theadjustable means freely disengaging from its support bracket.

11 Claims, 2 Drawing Figures ENERGY ABSORBING STEERING COLUMN BACKGROUNDOF THE DISCLOSURE This invention relates generally to-energy absorbingsteering column assemblies for motor vehicles, and more particularly toa method for mounting a steering column in a vehicle.

Conventionally, the upper end of an energy, absorbing or collapsiblesteering column is supported by a bracket that is normally rigid butwhich gives way in the event of abnormal loading. Such brackets usuallydepend upon the shearing or deforming of plastic or metal parts for thatfunction. Such brackets are vulnerable to damage when being transportedor stored prior to assembly.

BRIEF SUMMARY OF THE DISCLOSURE According to the presently preferredembodiment of this invention, a motor vehicle steering column has thefollowing features:

a. an energy absorbing steering column assembly is supported at itsupper end by its engagement with a bracket rigidly affixed to the bodystructure of the vehicle;

b. interengaging formations on the bracket and the steering column arefreely disengageable upon downward movement of the upper end of thesteering column; and

c. such downward movement is normally prevented by reaction of the lowerend of the column against vehicle body structure.

The interengaging formations on the body supported bracket and thesteering column may include threadedly adjustable means to secure thecolumn in position during normal usage.

BRIEF DESCRIPTION OF THE DRAWINGS The many objects and advantages of amotor vehicle steering column constructed in accordance with thisinvention will become apparent upon consideration of the followingdetailed discussion and the accompanying drawings, in which:

FIG. 1 is a side elevational view, partly in section, of a steeringcolumn assembly embodying the invention;

and

FIG. 2 is a side elevational view, partly in section, of a modificationof the lower support for the steering column shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawings, wherein the presently preferred embodiments of a steeringcolumn assembly constructed in accordance with this invention isillustrated, FIG. 1 shows a column assembly installed in a motorvehicle. The energy absorbing steering column 10 includes a tube 11having a corrugated section arranged to plastically deform or collapseunder an axial impact load and to absorb at least some of the impactenergy.

A two-piece telescopic steering shaft assembly 12 is supported bybearings within the corrugated tube 11. A steering wheel 23 is connectedto theupper end of the shaft assembly 12. The lower end of the shaft 12is constructed to be connected to a steering gear.

An upper bracket 13 is rigidly affixed to the body structure 14 of amotor vehicle which may comprise a portion of an instrument panel. Thebracket 13 has a pair of depending flanges in which tapered sockets 15are formed.

A bracket 16 is welded to the upper side of the corrugated tube 11 andhas a pair of upstanding flanges spaced from the depending flanges ofthe bracket 13. Weld nuts 17 on the flanges of the bracket 16 eachreceive a bolt 18 having a head that forms a tapered projection 19.

The weld nuts 17 are so positioned that when the steering columnassembly 10 is in its operative position, each projection 19 isengageable with a respective socket 15. I

The steering column assembly 10 is mounted in the vehicle by insertingits lower end through an aperture 20 in the toe board portion of thevehicle body floor pan 26. The aperture 20 is lined by a rubber ring 21against which the lowermost of the corrugations 22 is seated. Duringinstallation, the steering column 10 is held in its operative positionwhile the bolts 18 are threaded rearwardly to bring the projections 19into engagement with the respective sockets 15.

When the bolts 18 are tightened, the steering column 10 will beeffectively trapped between its lower engagement with the body structure26 and the engagement with the bracket 13. The bolts 18 are tightened sothat the column tube 11 is loaded very lightly in compression. Thisprovides a positive engagement preventing rattling of the severalsteering column parts.

It will be readily appreciated from FIG. 1 that although the steeringcolumn 10 is rigidly supported during normal loading, there is nothingto oppose axial forward collapse of the corrugated tube 11. Theprojections 19 and the sockets 15 are aligned with the steering columnaxis. The projections 19 readily disengage from the socket 15 in theevent an impact load is exerted against the steering wheel 23 wherebythe corrugated tube 11 is free to collapse.

The toe board portion of the floor pan 26 acts as a reaction member bothfor the support of the column 10 when the bolts 18 are tightened and forthe collapse of the corrugated section of the tube 11 when an impactload is imposed on the steering wheel 23.

ALTERNATE EMBODIMENT FIG. 2 illustrates an alternate embodiment of asteering column constructed in accordance with this invention. In thisalternate embodiment, the support for the upper end of the steeringcolumn may include the threadedly adjustable projections 19 or it mayinclude projections that are fixed with respect to the steering columnbracket 16. In either case, the embodiment of FIG. 2 includes taperedprojections affixed to the steering column at its upper end and whichengage tapered sockets formed in a bracket fixed to body structure.

The distinguishing feature of the FIG. 2 embodiment is the supportprovided for the lower end of the column. A thrust ring 24 of annularconstruction engages the lowermost corrugation 22 of the corrugatedcolumn tube 11. Bolts 25 extend through the thrust ring 24 and engagethe floor pan 26. When the bolts 25 are tightened, the column 11 isdisplaced rearwardly causing the projections 19 to engage the sockets15.

The column of FIG. 2 operates in the same manner as the column ofFIG. 1. In both embodiments, the upper end of the column is free todisengage from-its support on the body structure when an impact loadupon the steering wheel causes the corrugated column tube to collapse.Disengagement of the column from the body in the area of the instrumentpanel is not dependent upon fracture of a frangible piece.

The foregoing description presents the presently preferred embodiment ofthis invention. Modifications and alterations may occur to those skilledin the art that will come within the scope and spirit of the followingclaims.

I claim:

1. An energy absorbing steering column for a motor vehicle having firstand second spaced-apart body structures,

said steering column having first and second spacedapart column supportportions,

first means constructed to support said first column portion on saidfirst body structure,

said first means being constructed to prevent forward displacement ofsaid first column portion,

second means supporting said second column portion on said second bodystructure,

said second means being constructed to prevent the rearward displacementof said second column portion,

adjustable means constructed to increase the effective length of saidsteering column supported between said first and second body structures,

said second means being constructed to permit unrestricted free forwarddisplacement of said second column portion with respect to said secondbody structure.

2. An energy absorbing steering column for a motor vehicle having firstand second spaced-apart body structures,

said steering column having first and second spacedapart column supportportions,

first means constructed to support said first column portion on saidfirst body structure,

said first means being constructed to prevent forward displacement ofsaid first column portion,

second means supporting said second column portion on said second bodystructure, I

said second means being constructed to prevent the rearward displacementof said second column portion,

One of said first or second means having adjustable means constructed toload a portion of said steering column between said first and secondcolumn portions in compression,

said second means being constructed to permit unrestricted free forwarddisplacement of said second column portion with respect to said secondbody structure.

3. An energy absorbing steering column for a motor vehicle having firstand second spaced-apart body structures,

said steering column having first and second spacedapart column supportportions,

said steering column having a plastically deformable energy absorbingsection situated between said first and second support portions,

first means constructed to support said first column support portion onsaid first body structure,

said first means being constructed to prevent forward displacement ofsaid first column support portion,

second means supporting said second column support portion on saidsecond body structure,

said second means being constructed to prevent the rearward displacementof said second column support portion, one of said first and secondmeans including adjustable means constructed to load a portion of saidsteering column in compression, said second means being constructed topermit the free disengagement of said second steering column supportportion from said second body structure upon deformation of said energyabsorbing section when a forwardly directed impact load is exertedagainst the rearward end of said steering column. 4.-An energy absorbingsteering column for a motor vehicle having spaced-apart body supportstructures,

said steering column including an outer tube having an axiallycollapsible energy absorbing section, said outer tube having a firstsupport portion disposed forwardly of said energy absorbing section anda second support portion disposed rearwardly of said energy absorbingsection, first means supporting said first outer tube support portion onfirst body structure against forward displacement, second meanssupporting said second outer tube support portion on second bodystructure, said second means being constructed to support said secondouter tube support portion against lateral and rearward displacement,said second outer tube support portion being freely displaceable in aforward direction with respect to said second body structure, adjustablemeans constructed to force said first outer tube support portion intoengagement with said first body structure and said second outer tubesupport portion into engagement with said second body structure. 5. Anenergy absorbing steering column for a motor vehicle according to claim4 and including:

said steering column including a telescopically collapsible steeringshaft rotatably supported in said outer tube. 6. An energy absorbingsteering column for a motor vehicle according to claim 4 and including:

said energy absorbing section comprising a corrugated portionconstructed to be plastically deformable under an impact load above apredetermined minimum. 7. An energy absorbing steering column for amotor vehicle according to claim 4 and including:

said steering column including a telescopically collapsible steeringshaft rotatably supported in said outer tube, said energy absorbingsection comprising a corrugated portion constructed to be plasticallydeformable under an impact load above a predetermined minimum, saidfirst means engaging the forward end of said corrugated portion. 8. Anenergy absorbing steering column according to claim 4 and including:

said adjustable means including a plurality of threaded memberssupported on said second outer tube support portion and havingrearwardly pointing tapered portions, said second body structure havingopenings receiving said tapered portions,

said threaded members being extendable to force said steering columnforwardly with respect to said second body structure and said firstouter tube support portion into engagement with said first bodystructure.

9. An energy absorbing steering column according to claim 4 andincluding:

threadedly adjustable means engaging said first outer tube supportportion and said first body structure, said threadedly adjustable meansbeing constructed to cause the rearward displacement of said steeringcolumn with respect to said second body structure and said second outertube support portion into engagement with said second body structure.

10. An energy absorbing steering column for a motor vehicle having avehicle toe board and a body mounted bracket,

said steering column including a telescopically collapsible steeringshaft and an outer tube surrounding said shaft,

said outer tube having an energy absoring collapsible section,

a first column portion situated forwardly of said energy absorbingsection,

an aperture in said toe board and said first column portion beingdisposed in said aperture,

reaction means supporting said first column portion on said toe board,

said body bracket having forwardly opening sockets,

said column having a second column portion spaced rearwardly of saidenergy absorbing section,

said second column portion having adjustable means constructed to engagesaid sockets of said body bracket,

said adjustable means being constructed to increase the effective lengthof said steering column supported between said toe board and said bodybracket.

11. An energy absorbing steering column according to claim 10 andincluding:

said adjustable means being constructed to load said energy absorbingsection in compression.

1. An energy absorbing steering column for a motor vehicle having firstand second spaced-apart body structures, said steering column havingfirst and second spaced-apart column support portions, first meansconstructed to support said first column portion on said first bodystructure, said first means being constructed to prevent forwarddisplacement of said first column portion, second means supporting saidsecond column portion on said second body structure, said second meansbeing constructed to prevent the rearward displacement of said seCondcolumn portion, adjustable means constructed to increase the effectivelength of said steering column supported between said first and secondbody structures, said second means being constructed to permitunrestricted free forward displacement of said second column portionwith respect to said second body structure.
 2. An energy absorbingsteering column for a motor vehicle having first and second spaced-apartbody structures, said steering column having first and secondspaced-apart column support portions, first means constructed to supportsaid first column portion on said first body structure, said first meansbeing constructed to prevent forward displacement of said first columnportion, second means supporting said second column portion on saidsecond body structure, said second means being constructed to preventthe rearward displacement of said second column portion, One of saidfirst or second means having adjustable means constructed to load aportion of said steering column between said first and second columnportions in compression, said second means being constructed to permitunrestricted free forward displacement of said second column portionwith respect to said second body structure.
 3. An energy absorbingsteering column for a motor vehicle having first and second spaced-apartbody structures, said steering column having first and secondspaced-apart column support portions, said steering column having aplastically deformable energy absorbing section situated between saidfirst and second support portions, first means constructed to supportsaid first column support portion on said first body structure, saidfirst means being constructed to prevent forward displacement of saidfirst column support portion, second means supporting said second columnsupport portion on said second body structure, said second means beingconstructed to prevent the rearward displacement of said second columnsupport portion, one of said first and second means including adjustablemeans constructed to load a portion of said steering column incompression, said second means being constructed to permit the freedisengagement of said second steering column support portion from saidsecond body structure upon deformation of said energy absorbing sectionwhen a forwardly directed impact load is exerted against the rearwardend of said steering column.
 4. An energy absorbing steering column fora motor vehicle having spaced-apart body support structures, saidsteering column including an outer tube having an axially collapsibleenergy absorbing section, said outer tube having a first support portiondisposed forwardly of said energy absorbing section and a second supportportion disposed rearwardly of said energy absorbing section, firstmeans supporting said first outer tube support portion on first bodystructure against forward displacement, second means supporting saidsecond outer tube support portion on second body structure, said secondmeans being constructed to support said second outer tube supportportion against lateral and rearward displacement, said second outertube support portion being freely displaceable in a forward directionwith respect to said second body structure, adjustable means constructedto force said first outer tube support portion into engagement with saidfirst body structure and said second outer tube support portion intoengagement with said second body structure.
 5. An energy absorbingsteering column for a motor vehicle according to claim 4 and including:said steering column including a telescopically collapsible steeringshaft rotatably supported in said outer tube.
 6. An energy absorbingsteering column for a motor vehicle according to claim 4 and including:said energy absorbing section comprising a corrugated portionconstructed to be plastically deformable under an impact load above apredetermIned minimum.
 7. An energy absorbing steering column for amotor vehicle according to claim 4 and including: said steering columnincluding a telescopically collapsible steering shaft rotatablysupported in said outer tube, said energy absorbing section comprising acorrugated portion constructed to be plastically deformable under animpact load above a predetermined minimum, said first means engaging theforward end of said corrugated portion.
 8. An energy absorbing steeringcolumn according to claim 4 and including: said adjustable meansincluding a plurality of threaded members supported on said second outertube support portion and having rearwardly pointing tapered portions,said second body structure having openings receiving said taperedportions, said threaded members being extendable to force said steeringcolumn forwardly with respect to said second body structure and saidfirst outer tube support portion into engagement with said first bodystructure.
 9. An energy absorbing steering column according to claim 4and including: threadedly adjustable means engaging said first outertube support portion and said first body structure, said threadedlyadjustable means being constructed to cause the rearward displacement ofsaid steering column with respect to said second body structure and saidsecond outer tube support portion into engagement with said second bodystructure.
 10. An energy absorbing steering column for a motor vehiclehaving a vehicle toe board and a body mounted bracket, said steeringcolumn including a telescopically collapsible steering shaft and anouter tube surrounding said shaft, said outer tube having an energyabsoring collapsible section, a first column portion situated forwardlyof said energy absorbing section, an aperture in said toe board and saidfirst column portion being disposed in said aperture, reaction meanssupporting said first column portion on said toe board, said bodybracket having forwardly opening sockets, said column having a secondcolumn portion spaced rearwardly of said energy absorbing section, saidsecond column portion having adjustable means constructed to engage saidsockets of said body bracket, said adjustable means being constructed toincrease the effective length of said steering column supported betweensaid toe board and said body bracket.
 11. An energy absorbing steeringcolumn according to claim 10 and including: said adjustable means beingconstructed to load said energy absorbing section in compression.